A touch sensor has been known as an interface for a user to input information to a display device. Arrangement of a touch sensor so as to overlap with a screen of a display device allows a user to operate an input buttons or icons displayed on the screen, by which information can be readily input to the display device. For example, US Patent Application Publication No. 2015/0130726 discloses an electronic apparatus in which a touch sensor is mounted on an organic EL display device. In this Publication, a sealing film is formed over an organic EL element (hereinafter, referred to as a light-emitting element) over which touch electrodes for a touch sensor are provided.